1. Field of the Invention
This invention relates generally to apparatus for injecting small amounts of concentrated fluids into a line which already carries flowing fluids. The invention relates to an all weather injector system and in particular to an injector system for injecting concentrated dye into flowing fuel lines of fuel loading terminals.
2. Description of the Prior Art
Governmental environmental regulations in the United States and other countries require that fuel be "marked" with a dye in order that it may be identified as having particular uses, quality standards or a certain tax classification. Prior apparatus for adding dye to fuel at a loading terminal includes a large storage tank of concentrated dye (typically filled from multiple 55 gallon drums), apparatus for diluting the dye, and a pump for forcing diluted dye to a plurality of conduits or supply lines and controls running to various loading islands where the diluted dye is injected into a flowing fuel line prior to loading into a tank truck or other conveyance.
Typically such storage tank, pump and supply lines are placed in the open air in proximity to the multiple fuel loading islands. High viscosity of the dye during cold weather conditions inhibits performance of the system, so such prior systems have provided heaters for the tank and for the supply line running from the tank to the diluted dye-injecting islands at the loading terminal.
Furthermore, such prior art fuel dilution apparatus takes the concentrated dye from the large tank and dilutes the concentrated dye with as much as ninety-five percent "carrier" by volume. Such carriers include diesel fuel, stove oil, xylene, and aeromatics which may be added to the dye without undue contamination of the fuel.
A carrier performs two functions in prior fuel dying apparatus. First, the carrier adds volume to the ratio of injected fluid to the fluid in the fuel line. Such added volume is generally necessary in such prior apparatus, because common pressurized meter pulsed injectors used to inject the dye into a fuel line are not capable of injecting low volumes typically found in common dye concentrates. Consequently, in order to overcome the limitations of such common prior equipment, the volume of the fuel dye concentrate must be increased through dilution from a concentrated level of five to thirty parts per million (ppm) (dye to fuel ratio) to as much as one thousand ppm.
The second function of using a carrier with prior fuel dying apparatus has been to reduce the effects of changes in dye viscosity due to changes in ambient temperature. Dilution of the dye concentrate does not completely eliminate the problem, however, as evidenced by the need of heating tanks, pipes, pumps etc., exposed to the weather at a terminal loading facility.